When is it possible to use BufRead and AsyncRead?

[bonsairobo]

https://github.com/alexcrichton/xz2-rs/blob/1a82c40d6d80171b7df328aea43b7054acd10c44/src/bufread.rs#L240C1-L241C59

I'm trying to figure out how to use XzDecoder with an async stream of bytes like you get from reqwest::Response::bytes_stream(). But I don't see how to transform the stream into something that implements BufRead. I don't really understand why BufRead is necessary in an async context either, where I would rather expect AsyncBufRead.

This is the closest I get:

    let stream = reqwest::get(url)
        .await?
        .error_for_status()?
        .bytes_stream()
        .map_err(|e| io::Error::new(io::ErrorKind::Other, e))
        .into_async_read();
    let decoder = XzDecoder::new(tokio::io::BufReader::new(stream));

But tokio::io::BufReader does not implement BufRead.

[bonsairobo]

It seems like this same problem applies to all different kinds of XzDecoder. Using any of them in an async context requires that they implement both the async and non-async versions of the io traits. E.g. AsyncRead + Read, AsyncWrite + Write, etc. I'm not aware of anything that implements both of these traits at the same time.

[bonsairobo]

Huh now I see this: https://github.com/alexcrichton/xz2-rs/pull/109

I guess I will give async-compression a try.